Those settings are good, the priority group should have sorted out the issue,
Yeah, the Barrier Device would be a problem if the spawnpads are inside it and its solid,
they would be OK if they are inside a hollow box mesh, or inside a bunch of barrier walls.
The other causes I know of for skyspawning are spawnpad team/class settings not matching the player,
and not enough spawnpads, 1 pregame and 1 game per player.